Also forgot to ask which engine ?
Viewing post in Extinction Denied jam comments
We pretty much spent all 10 days working on this one to polish it up, all the way up to the final 5 minutes before the submission deadline, haha.
The engine used was Unreal Engine 4.23, because that's the most recent version of Unreal that lets you export HTML games.
Sorry to hear it was hard to play due to the colors, but thank you for playing regardless, and thanks for the comments!